Traversing mechanism



June 20, 1961 1.. MARGASON 2,989,258

TRAVERSING MECHANISM Filed Dec. 24, 1958 2 Sheets-Sheet 1 I no. 4

INVENTOR. zzsrezq A. flAROASO/V HTTOk/VE'Y June 20, 1961 L. 1.. MARGASON2,989,258

TRAVERSING MECHANISM Filed Dec. 24, 1958 2 Sheets-Sheet 2 INVENTOR. 4:-54 4 mnecnso/v l I t I III nrroklvf) United States Patent 2,989,258 vTRAVERSING MECHANISM Lester L. Margason, Oakmont, Pa., assignor toPittsburgh Plate Glass Company, Allegheny County, Pa., a corporation ofPennsylvania Filed Dec. 24, 1958, Ser. No. 782,700 4 Claims. (Cl.242-43) 7 The present invention relates to apparatus for winding astrand of fibers on a tube and it has particular relation to a mechanismfor rapidly traversing the strand on a tube While it is being wound at ahigh rate of speed.

' In the production of continuous filament, textile, glass fibers, anumber of glass filaments are drawn from a molten supply of glass at ahigh rate of speed, i.e., 5,000 to 20,000 feet .per minute. The glasspasses through orifices in a bushing and forms cones of glass at thetips of the orifices. The individual filaments are drawn from the conesof glass and are grouped together into a strand as they pass over aguide. The strand is thereafter wtund in an open wind on a rapidlyrotating forming tu e.

There is no twist in the strand as it is thus formed and a binder isapplied to the filaments prior to the winding of the strand on the tubein order to bond them together and maintain the integrity of the strand.An open wind, rather than a parallel, level wind, is desired on theforming tube in order to aid removal of the strand from the tube. If aparallel, level wind is used, the untwisted strand is very difficult toremove when the filaments become broken. In this event, successive turnsof the strand become entangled and it soon becomes impossible to unwindthe strand and remove it from the tube. The open wind is such that thestrand is traversed through a substantial length of the tube for arelatively few turns of the strand on the tube, i.e., 2 to or more turnsfor a six inch long package for each traverse of the length of the tube.With this type of wind the succeeding turns of the strand cross eachother at a minimum angle of at least about 5.

The spiral wire traverse shown in US. Patent No. 2,391,870 has been usedfor traversing a strand at a very high rate of speed on a forming tube.In operation, the pair of conical spiral, wire cams mounted on therotating shaft of the traverse cause the strand to be positively movedalong the forming tube and returned by the sucrcessive engagement of thestrand with the cams. As the strand reaches the end of one cam, itsmotion is interrupted by it being contacted with the other cam and it isimmediately started on its return movement to the other end of the othercam. This change or transfer of the strand from one cam to another hasbeen observed to be quite abrupt, and the strand undergoes a physicalbeating upon this transfer from one cam to the other. Sometimes the camsbecome sprung during operation and "the strand is held momentarily atthe end of the traverse and then springs back abruptly. The beating andabrupt 'change in direction have caused breakage of some of thefilaments. As soon as a few of the filaments become broken, the drawingoperation usually is interrupted.

It is an object of the present invention to provide a traverse mechanismfor rapidly traversing a strand as it is ,wound at a high rate of speedon a tube which mechanism does not require the transfer of the strandfrom one cam to another. It is a further object of the invention toprovide a traverse mechanism which produces a smooth change in directionof the strand at the end of its traverse without unduly subjecting thestrand to a physical beating. It is a further object of the presentinvention to produce a traverse mechanism which is easy and inexpensiveto make, maintain and operate.

Patented June 20, 1961 These and other objects of the invention areaccomplished by means of a single wire which is in the shape of an S or.a Z and which is cap-able of being rotated at a high rate of speed. Theinvention and its method of operation may be more fully understood byreference to the description of the drawing in which:

FIG. 1 is a diagrammatic view of glass fiber forming apparatus includingthe. traverse mechanism of the present invention;

FIG. 2 is an elevation of the traverse mechanism;

FIG. 3 is an end view of the traverse as shown in FIG. 2;

FIG. 4 is an end view of the traverse mechanism rotated upon its axisfrom the position of the traverse shown in FIGS. 2 and 3, and

FIGS. 5 to 15 illustrate diagrammatically the movement of the strand 0nthe traverse during rotation of the traverse.

In FIG. 1 of the drawing there is shown a glass melting furnace orforehearth thereof 10 containing a supply of molten glass 11 and havinga bushing 13 attached to the bottom of the furnace. The bushing isprovided with a series of orifices in the form of tips 14 through whichthe molten glass fiows and forms in small cones 15 suspended from thetips of the orifices 14. The tips are usually formed in a number ofrows, for example, 4 to 6 or more rows having a great many tips in eachrow so that the total number of tips is about 204 in number. A smalleror greater number of tips may be present in the bushing,

Glass filaments 16. are pulled from the cones 15 at a very high rate ofspeed, i.e., 5,000 to 20,000 feet per minute, and wound on a rapidlyrotating forming tube 18 which may be approximately 6 inches in outsidediameter and may rotate at approximately 6850 to 7600 revolutions perminute. The glass filaments are grouped into a strand 19 as they passover guide 20 prior to their being wound on the tube 18. Usually aliquid binder and lubricant 'such as -a combination of starch andvegetable oil are applied to the filaments in the strand as they passover a felt pad on the guide, which pad is saturated with the binder andlubricant. The binder and lubricant may be dripped onto the pad by meansof an applicator 22.

inch diameter brass rod which has been bent in substantially a singleplane in'the form of an S or a Z inter.- mediate itsends. The rodextends generally in an axial direction. with successive portions of therod being laterally displaced from the axis first on one side of theaxis and then on'the other side of the axis. The center of the rod withrespect to the mid-point of travel of the strand along the traverse isin the axis of rotation of the rod. The laterally displaced portionsshould be symmetrical so as to avoid undue vibration of the traverseduring rotation. The portions of the traverse which are farthest fromthe axis may be bent slightly in a smooth curve from the general planeof the traverse, i.e., at 2 to 45, in the direction of rotation of thetraverse. This permits the traverse to intercept the strand a littlesooner in its travel toward the end of the throw and permits the changein direction to be a little smoother than if the bends were not present.

The rod or shaft is connected to a motor 29 which is mounted on amovable base 30. The axis of the rod 26 is parallel to the axis of thetube 18. The traverse 24 is located adjacent tube 18 so as to cause thestrand 19 to curve around the traverse 24 at all times in its travelfrom the guide to the tube. In other words, the axis of the traverse isolfset laterally several inches A from a line drawn from the guide tothe periphery of the tube 24 where the strand first contacts the tube sothat it is more in line with the guide and the axis of the tube 18. Thetraverse 24 may be made to reciprocate in the direction of its axis bymoving it, the motor 29 and the movable base 30 on which the motor isattached by means of a reversible motor 32 which is attached to the baseto cause the base to move in slideway 34. The traverse 24 may bemaintained in a stationary position while it rotates and the tube 18 mayinstead be reciprocated axially.

The position of the traverse 24 with respect to the tube 18 and also theposition of the strand 19 on the traverse during its travel between theguide and the tube are illustrated in FIGS. 3 and 4. FIGS. 2 and 3 showthe strand at the mid-point of its travel on the traverse and when thetraverse is not rotating. This is at a time when the general plane ofthe traverse is substantially parallel to a straight line between theguide and the tube. When the general plane of the traverse issubstantially parallel to the travel of the strand during rotation ofthe traverse, the strand will be at one end or the other of thetraverse. It can be seen from FIGS. 3 and 4 that the traverse 24 isalways placed with respect to the guide 20 and tube 18 so that thestrand is slightly displaced and there is tension on the strand whichcauses it to move against the traverse.

The movement of the strand with respect to the traverse while it isrotating is illustrated by the series of positions of the traverse shownin FIGS. 5 to 15. These figures are diagrammatic views looking in adirection along the line of travel of the strand from the guide to thetraverse. Since the strand is always under tension, it will tend to movealong the length of the rod 26 to the point where there is the leastamount of tension. Thus, assuming that FIG. 5 represents the traverse atrest, the strand 19 will be at the center point 35 of the traverse orthe point where the rod 26 passes through the axis of the traverse. Asthe rod rotates, as shown in FIG. 6, the strand will move to the lefttowards the depression 36 in the rod which is removed from the axisbecause the strand is seeking the path of least resistance. This travelis continued in FIG. 7 where the rod has rotated through approximately90. As the rod continues to rotate past 90 to 135, as shown in FIG. 8,the tension on the strand begins to increase and this slows down thesidewise travel of the strand. The bend of the outermost portion of thedepression 36 into the direction of rotation causes this slowdown tobegin before the strand gets to the end of the depression and makes thechange in direction smoother. The travel of the strand to the leftceases as the rod has rotated approximately 180 as shown in FIG. 9.

As the rod rotates past 180 to 225, the strand begins to move to theright to a point of lesser tension, as shown in FIG. 10, and will moveacross the center point 35 of the rod as shown in FIG. 11 to seek thedepression 38 in the rod which is on the other side of the center point35 of the traverse. In FIG. 12 the rod has rotated through 315, and thestrand is beginning to slow down in its travel to the right. In FIG. 13the rod has rotated 360 and the strand 19 has been stopped in itsmovement to the right and is ready to begin or has begun its returntravel to the left as shown in FIG. 14. In FIG. 15, the strand 19 isapproaching the center point 35 in movement along the length of thetraverse toward the left again. This cycle is repeated over and overagain during the rotation of the traverse. The tension on the strand isthe driving force which causes the strand to move laterally along therod. This is in contrast to the traverses of the prior art which havepositively displaced the strand.

The length of throw or traverse of the strand can be controlled by theamount of tension which is put on the strand by the placement of thetraverse with respect to the tube 18 and guide 20. The more tension thatis 4 applied, the greater is the length of throw and conversely the lesstension that is applied, the smaller is the length of throw. The angle aat which the central portion of the rod crosses the center point 35 oraxis of the traverse also determines the length of throw of thetraverse, the greater the angle, the faster the strand 19 tends to moveaway from the center point 35 of the traverse to the right or leftdepending upon which is the path of least resistance. The rate ofrotation of the traverse also affects the length of throw, the higherthe rate of rotation, the shorter the length of throw. The combina tionof the tension caused by displacement of the traverse against the pathof the strand and the angle of crossing of the rod 26 with respect tothe axis of the traverse should not be so great that the strand 19 isthrown past the outermost points of the depressions 36 and 38 of thetraverse. In this event, the strand will dwell outside the end of thetraverse. If it dwells outside the end of the traverse closest to themotor, it will probably break. If it dwells outside the end away fromthe motor, it will probably come back onto the traverse, but the packagebuild-up will be non-uniform. The axial distance 1" between theseoutermost points should be greater than the length of throw desired.

The following conditions are exemplary of the operation of the traversein the formation of glass fibers. The strand 19 may be traveling at aspeed of 11,000 to 13,000 feet per minute and the distance between theguide 20 and the tube 18 may be approximately 25 to inches. The traverse24 will be located as close to the tube 18 as possible withoutcontacting the package of strand on the tube. This gives best control ofthe lay of the strand on the package. The traverse 24 may be offsetperpendicularly from a line drawn from the guide to the surface of theforming tube by about 1 to 3 inches. The traverse may rotate at about1800 to 1900 revolutions per minute and reciprocate axially 6 times aminute. The outermost points of the depressions in the rod 26 may be 1to 2 or more inches in a perpendicular distance d from the axis and theymay be 3 /2 to 5 or more inches apart in an axial distance t. The anglewhich the central portion of the rod 26 forms with the axis of thetraverse may be about 45, but may vary widely, for example by about 20to 70. These conditions are suitable for traversing the strandapproximately 1 /2 to 2 /2 inches on the tube during rotation of thetube. The traverse of the present invention can be employed in theapparatuses shown in the copending applications of Franklin H. Green,Serial No. 782,417 filed December 23, 1958 entitled Fiber FormingApparatus and Serial No. 782,429 filed December 23, 1958 entitledApparatus for Forming Fibers.

It can be seen that if the rod is rotating in the neighborhood of 1800to 1900 revolutions per minute, the strand will move back and forth overthe rod quite rapidly. The use of the curved rod or wire as a traversemechanism permits the change in direction of traverse of the strand tobe accomplished very smoothly and greatly minimizes the physical beatingwhich the strand under" goes in the prior art devices. The traversemechanism of the present invention is simple and inexpensive to make,maintain and repair. Slight variations in the symmetry of the curvatureof the offset portions in the rod can be tolerated and a uniform packagecan be produced.

Although the invention has been described with respect to specificdetails of certain embodiments thereof, it is not intended that suchdetails be limitations upon the scope of the invention except insofar asincluded in the accompanying claims.

I claim:

1. An apparatus for traversing a strand of fibers while it is beingwound on a tube which comprises a rod having a portion of its lengthintermediate the ends curved in substantially the form of a Z and meansfor axially rotating the rod.

2. An apparatus for traversing a strand of fibers as it is being woundon a tube which comprises a rod having symmetrical portions intermediateits ends which are alternately and oppositely, laterally displaced fromthe general axis of the rod and means 'for axially rotating the rod.

3. An apparatus for traversing a strand of fibers while it is beingwound on a tube which comprises a rod extending generally in an axialdirection with successive portions of the rod being laterally offsetfrom the axis on first one side of the axis and then on the other sideof the axis and means for axially rotating the rod.

4. An apparatus for traversing a strand of fibers while it is beingWound on a tube which comprises a rod extending generally in an axialdirection with successive portions of the rod being laterally andoppositely otfset 6 I from the axis on first one side of the axis andthen on the other side of the axis and with the outermost section ofeach of the oifset portions being curved in the direction of rotation ofthe rod, and means for axially rotating the rod.

References Cited in the file of this patent UNITED STATES PATENTS1,990,620 Schweiter Feb. 12, 1935 2,433,304 Stream Dec. 23, 1947 FOREIGNPATENTS 454,062 Great Britain Sept. 23, 1936 691,328 Great Britain May13, 1953 209,963 Switzerland Aug. 16, 1940

